ESPUSB is a software-only USB device stack that adds low-speed USB capability to ESP8266 and ESP8285 microcontrollers. It implements the USB protocol primarily in software instead of relying on dedicated USB hardware. The design needs only a small amount of external circuitry and uses adjacent GPIO pins for the D+ and D- signals. It operates at USB low speed, making it suitable for human-interface devices and control-oriented peripherals. The repository includes an example that emulates a...